The present invention is directed to a device and a method for managing communications between data communications systems, specifically a device and a method for managing communications between a wireless data communications system and a wired or wireline data communications system.
A topic of increasing interest in the communications industry is the integration of wireless technologies, e.g., cellular technology, with wired or wireline technologies, e.g., computer networks, such as those connected over the World Wide Web. It is thought that by integrating the two technologies together, a communications system of even greater flexibility may be achieved, such that communications between extremely remote parts of the earth may be possible.
Of course, it is a truism in the computer industry that computers will only provide appropriate outputs if the inputs are carefully managedxe2x80x94garbage in, garbage out. Thus, it is necessary to have a high level of accountability for the data transmitted by wireless systems in order for those systems to be integrated with wired systems. Otherwise, it would not be practically possible to support the desired systems integration.
It is well known in the cellular industry to provide such methods of accountability and quality control for data communicated over a wireless system. For example, it is known to divide the data messages to be communicated between, for example, a fixed base station and a mobile station into a plurality of blocks. Each individual block is assigned a block identifier so that the receipt of each block can be confirmed. Thus, in operation, when a data message is sent from an originating station, for example the base station, to a receiving station, for example the mobile station, the mobile station first determines whether all the blocks of the message have been received. If it is determined by the mobile station that less than all of the blocks have been received, or that some of the blocks have been corrupted by noise, for example, the mobile station will send a request repeat signal to the base station. The request repeat signal makes the base station aware that less than all of the blocks sent were successfully received by the mobile station, and provides the base station with the identifiers for those blocks which were not successfully received. In response, the base station transmits to the mobile station a second message including only those blocks which were not previously successfully received. The procedure is repeated until all the blocks of the message are successfully received by the mobile station.
At this point, the mobile station reassembles all of the blocks of the message, and prepares the message for transmission to, for example, a first computer coupled to the mobile station. For example, the message may be formatted into Internet Protocol (IP) format, i.e., having an Internet Protocol header and one or more atomic Internet Protocol data fragments. The message may then pass from the first computer through a series of routers to a second computer at another location.
The above-described system and method have some clear disadvantages. It is necessary for the receiving station to have a considerable amount of buffer memory dedicated to the storage of the blocks of an incoming message until the incoming message can be reassembled. Further, it is necessary for the receiving station to devote a considerable amount of processor time to the reassembly of the blocks into the incoming message once all of the blocks have been received. The speed of the processor is important in this respect, because the operation of the processor can limit the throughput of the wireless/wired system. In the end, the need for additional memory capability and additional processor speed can only be met by increasing the overall cost of the system to the customer or by forgoing other functionalities.